Thanks for the question Shannon,
The situation, which you describe, is simply termed "frost crack". This phenomenon is common and usually does not pose any immediate threat to the tree. Treating the crack with sealants or paints is typically unnecessary and not advised. Water in the inner bark and the wood expands and contracts as the result of freezing winter nights and warmer, sunny winter days (rapid fluctuation of temperature). Some species are more susceptible to frost cracks, especially if the tree is not native or genetically adapted to the area.
There is no way to predict these “frost crack” events. Some horticulturists and arborists suggest wrapping your tree with paper tree wrap or applying white latex paint on the main stem to prevent initial frost cracking. I personally think painting trees to prevent frost cracking is aesthetically displeasing to the eye.
Regardless, once a frost crack develops, there is not really anything you can do other than monitor the tree.
Hope this helped!